@GTE who wrote
IIRC, the AAIB report on the 777 prang at LHR concluded that partially raising the flaps had no significant effect upon the outcomes.
G
That's not what the report says:
Direct quote from the AAIB (below) shows that without the flap reduction the 777 would have crashed through the ILS antenna:
As it was, the flap reduction moved point of ground contact 50m towards the runway threshold, missing the ILS:threshold
quote from AAIB Report:
Actions of the Commander
The Commander, on realising that he was unable to obtain any additional thrust from the engines, attempted to reduce drag of the aircraft by reducing the flap setting. However, the aircraft was now so close to the ground that there was little time for the beneficial effects of this action to take effect.
The action in reducing the flap setting was prompt and resulted in a reduction of the aerodynamic drag, with minimal effect on the aircraft stall speed: it moved the point of initial ground contact about 50m towards the runway threshold. Had the flaps remained at FLAP 30, the touchdown would have been just before the ILS antenna, but still within the airfield boundary. The effects of contact with the ILS antenna are unknown but such contact would probably have led to more substantial structural damage to the aircraft.
OK the pilot in his book thought he would have hit houses but his actions IMHO (and those of the AAIB) despite the lateness of the flap reduction, obtained some benefit .
I took a particular interest in this accident as at the time one of our aeroplane group members was a BA777 Captain, knew PB and I discussed it with him extensively.
Cusco